Windraider is the name given to improvements to the Wind Wing (U.S. Pat. No. 8,734,084), the Wind Wing Electrical Generator (U.S. Pat. No. 8,860,240).
The Wind Wing was conceived as a means of converting wind energy into electrical energy with a minimal displacement of mass.
It was the belief of the inventor that a vertical symmetrical unarticulated airfoil, capable of rotating around a vertical mast could be engineered to oscillate in the wind. And that following Faraday's Law of Induction, a section of a coil mounted on the airfoil's trailing edge would, in the presence of a nearby magnet have a current induced within it. That wind energy might be converted into electrical energy with such a minimal displacement of mass raised the potential that it might produce a simpler, more reliable, and less expensive alternative to other methods of converting wind energy into electrical energy.
A small wind tunnel was constructed using a variable speed DC (automobile radiator) motor, and different symmetrical unarticulated airfoils shapes were fabricated and tested. None was able to achieve oscillation.
The problem is that as a symmetrical articulated airfoil with a zero angle of attack to the wind rotates, lift diminishes in the direction its tail rotates toward; while at the same time it increases in the reverse direction. Most symmetrical unarticulated airfoils will flutter or vibrate, but they will not oscillate across any substantial range or in a regular manner
The testing did reveal however, that the force keeping a symmetrical unarticulated airfoil with its chord parallel to the wind inside a structure surrounding it were stronger than anticipated. This led to two coincident efforts. The first was to develop a spoiler which could, in synchronization with a symmetrical unarticulated airfoils rotation, disrupt the lift on one side and then the other. The idea was that with powerful lift forces acting on both sides, inhibiting them on one side would allow the other side to dominate. The second was to take advantage of web-accessible computational fluid dynamic programs (JavaFoil, NASA FoilSim, etc. These revealed that by selecting and positioning relative to one another, three vertical airfoils close to NACA 4-digit symmetrical airfoils, and positioning them bows to wind, air flow velocity in specific sections of the channels between them would be increased, and static pressures decreased to shocking degrees.
To as much as possible maintain this source of force while still capturing wind energy and converting it into mechanical energy a scheme of segmenting and expanding the center airfoil into a Forward nacelle, an oscillating part (named the Oscillating wing) and an Aft nacelle was invented. When a model incorporating this scheme was constructed and tested, the Oscillating wing oscillated regularly over a range of almost 60 degrees. No spoiler was required and the effort to develop one was abandoned.
While not recognizing it at the time, this turned out to be an element of a previously undiscovered means of converting wind energy into mechanical energy, later named the Windraider process.
Coincident with these developments, a method of wrapping the coil around the Oscillating wing, such that it would allow magnets to be positioned on fore and aft of its aft section was invented. It was nearly simultaneously recognized that two L-shaped iron bars, their longer ends holding magnets, positioned with their short ends placed flush against the long ends of the other constitute a permanent magnet dipole, an arrangement that creates a lower-than-air-resistance path for magnetic flux between the poles of two closely positioned similarly aligned magnets or arrays of magnets. And which, with the invented wrapping arrangement allows the flux of between the two outside poles of these magnets to pass over rather than through the intervening aft section of the coil where it would otherwise almost totally negate the flux passing between the inside poles. This allowed the flux density through which the aft side of the coil oscillated could be doubled—which following Faraday's Law of Induction, doubles the voltage induced in the coil. This arrangement of magnets and iron bars was named the Dipole Permanent Magnet Assembly, abbreviated DPMA. Its distinguishing benefit is that by doubling the magnetic flux, it allows the same voltage to be induced with half the number of coil wraps.
At some point it became apparent that such machine could not only cost very little compared to other methods of converting wind energy into electrical energy, but could be fabricated by almost any community anywhere in the world by local crafts people using locally available materials. The potential that this could provide a meaningful amount of electricity to a significant portion of the estimated 25% of the world living without electricity became the dominant objective.
Pursuing this objective, it was recognized that a virtually abandoned (in the early 1900s) technique of creating strong magnets called “compound magnets” could be fabricated in these communities. Further, that aluminum soft drink cans melted (aluminum having a relatively low melting point, low specific gravity and high conductivity) drawn into wire and then coated with a combination of locally available ingredients producing magnet wire for its coils. Given this, it appeared, and still does that a Wind Wing capable of providing sufficient electricity to light two small rooms or charge the battery of a small computer or smartphone can be fabricated in many parts of the world for not much more than $20. This is the basis for the “$20 Model.” Other models are referred to as “Tower Models.”
Up to that point, little attention was paid to other models. Instead, because their appeared no known prior instance of wind energy being converted into mechanical energy by means the inventor had stumbled upon, focus was directed toward understanding the phenomena. The phenomena itself was eventually named the “Windraider process,” its control and construction of an effecting machine is the subject of related Claims in this application.
To help determine the nature of the Windraider process—which turned out to be surprisingly complex and sophisticated—the Wind Wing model was mounted on the top of the inventor's car and driven up and down an abandoned airfield, with videos being made of the Oscillating wing's rotations, the videos later allowing determination of the Oscillating wing's instantaneous rotational speed and the combination of the generated car speed and the headwind. (i.e. the Apparent wind).
One of the surprising results of this experiment was that it showed the Wind Wing's structure to be particularly aerodynamically robust: A foamboard and paper model 18-inches high withstanding and continuing to operate in apparent wind speeds in excess of 50 MPH, 20 MPH beyond where every widely known wind turbine begins to self protect itself by furling its blades, and 10 to 15 MPH beyond where all but the largest and most sophisticated turbines have already shut down. It also happened that during a trial run before the camera was mounted and recording begun, the inadequately secured Wind Wing model blew off the top of the car and went bouncing down the runway. When it was recovered, it was found to have suffered no noticeable damage and was functioning perfectly.
In the Fall of 2012 an effort was made to have further development of the Wind Wing taken over by the National Renewable Energy Laboratory (NREL) an arm of the Department of Energy. The offer was rejected on the basis that such was not within the NREL's charter, but with the benefit that the Director of the NREL suggested that inventor's further development focus on how the Wind Wing might perform burdened with a load, and that the inventor file a US Patent Application.
Following rejection by the NREL and partially on the basis of its recommendation, in December 2012 the inventor applied for a US patent on the Wind Wing apparatus. In October 2013, a USPTO Office Action dictated this Application be divided, leading to two Applications, one resulting in the US Patent for the Wind Wing (U.S. Pat. No. 8,734,084) and the other a US Patent (U.S. Pat. No. 8,860,240) for the Wind Wing Electrical Generator.
While awaiting action on these Patent Applications, the inventor, following the recommendation of the Director of the NREL to focus on the Wind Wing's ability to carry “a load” engineered the Torsional transfer mechanism, which was included in the Aug. 20, 2014 Provisional Patent Application (62/038,493) and is one of the Claims of this Application.
The Torsional transfer mechanism recognizes the burden of “a load” is disproportionately inhibiting when the Oscillating wing is amidships and Static pressures of air flowing over each of its sides are nearly equal. It unburdens the Oscillating wing from whatever “load” it is connected to (in this instance, the coils of the Armstrong generator) until the Oscillating wing is oscillating beyond a threshold arc where the difference in Static pressure is sufficient to overcome the burden of the inertia of the “load.”
In late 2013, the inventor found on the Internet a paper be two faculty members of the Georgia Institute of Technology School of Aerospace Engineering analyzing another oscillating wing power device, the Wind Fin, concluding, among other things, “Equally sized WFs [Wind Fins] and HAWTs {Horizontal Access Wind Turbines] provide comparable output power. Until he read this, the inventor believed the Wind Wing was capable of producing no more than considerably less than a well engineered wind turbine, especially a Horizontal Access Wind Turbine (HAWT). generally recognized to produce more power than a Vertical Access Wind Turbine (VAWT). Inasmuch as the inventor believed, and still does that the Wind Wing is a stronger, more reliable, less expensive and more efficient design than a Wind Fin for converting wind energy into electrical energy, this opened the potential for it to become a commercial machine and perhaps most importantly a effective and highly deployable weapon in the United States' battle against global warming.
It is a physical characteristic of higher speed winds that they contain more kinetic energy than lower speed winds. In fact, the kinetic energy of the wind is proportional to its velocity cubed. It is also generally accepted that in most locations wind speeds increase with elevation above the ground, the result of ground features (trees, buildings, etc., even the surface of calm water) exerting friction on the wind. The proven (from car testing) ability of the Wind Wing to operate in apparent wind speeds higher than tolerated by turbines suggested it will be a better alternative to wind turbines in many situations simply by positioning it higher in wind speeds where they are unable to function. The ability of the Torsional transfer mechanism to allow it to drive heavier coil loads encourages this perspective. Two new inventions, both included in the Claims of this Application advance it.
The first of these is what the inventor named the Yeager wing in honor of Chuck Yeager, the man who first broke the sound barrier. It is a collapsible Oscillating wing which, when fully collapsed, allows the Oscillating wing to, along with the Wind Wing's Forward and Aft nacelles, assume a form aerodynamically indistinguishable from the NACA 4-digit streamlined symmetrical airfoil from which they were originally configured.
NACA 4-digit airfoils were originally published in 1929-1933 by the National Advisory Committee on Aeronautics, (NACA) the predecessor agency to NASA. These airfoils suffer remarkably little drag (Coefficients of Drag in the range of 0.05 versus that of bare poles whose range is approximately 0.45) allowing wind to pass around and through Wind Wings with very little loss of speed and kinetic energy. Presenting three NACA 4-digit streamlined symmetrical airfoils (each nearly the height of the Wind Wing) means that a Wind Wing can stand up in the face of extraordinarily powerful winds without damage.
It also opened the possibility of the Wind Wing not only being able to avoid furling and shutting down in wind speeds where a turbine would be required to do so, but being able to convert wind energy into mechanical energy in even higher wind speeds by just partially collapsing. Facilities to test the limits of this are beyond the access of the inventor. but there is no reason to believe that the Wind Wing might not be able to convert wind energy into mechanical energy in speeds in excess of 60 MPH and beyond—except that no generator thus far invented appears capable of withstanding the shock of oscillating motion such speeds would produce.
To control the opening and closing of the Yeager wing, the inventor engineered a programmable proportional controller for which he filed a Provisional Patent Application, No. 62/184,438 on Jun. 25, 2015.
The Programmable proportional control mechanism uses the Yeager wing's oscillating motion's centrifugal force to drive outward a weight hinge connected to two arms which are themselves connected to the collapsible sides of the Yeager wing. As the Yeager wing oscillates more rapidly in response to higher speed winds, its oscillating rotational speed increases, increasing the centrifugal force on this hinge driving it further outward and closing the collapsible sides of the Yeager wing. This closing force is resisted by an elliptical spring increasingly forcing the collapsible sides of the Yeager wing toward opening as it closes. Eventually equilibrium is reached so that there is a degree of closure for each wind speed. This degree of closure is also partially determined by a program bar allowing the equilibrium point for each wind speed to be programmed by the user, and with the program bar interchangeable, different programs matched to different local environments.
This capability allows the degree of closure of the Yeager wing to be optimized to a range of local conditions which themselves might change depending upon the time of the year. For example, in the summer there might be less but more steady wind. While in the Winter, the wind might be stronger. And in the Spring and in the Fall there might be more gusty wind than otherwise. Most importantly, where wind speeds are such that they would cause any component to fail, the Programmable proportional control mechanism can close the Yeager wing so that it no longer oscillates and presents what are essentially NACA 4-digit streamlined symmetrical airfoils to the wind.
Shortly after the Torsional transfer mechanism with its capacity to accommodate a greater “load’ was engineered, there appeared another natural evolution of the Patented Wind Wing (U.S. Pat. No. 8,860,864) Electrical Generator, here named the Armstrong Electrical Generator (or simply the “Armstrong generator”), in honor of Neil Armstrong, one of the inventor's heroes. The Armstrong generator takes the Dipole Permanent Magnet Assembly, DPMA, from the Wind Wing Electrical Generator, increases it by a factor of 4 mounting them symmetrically around a Mast that elevates the Oscillating wing or Yeager wing high enough above the ground to take advantage of the higher speed winds there present. It also employs two coils rather than the Wind Wing Electrical Generator's one coil, wrapping them also symmetrically around the Mast and taking advantage of greater coil mass allowed by the Torsional transfer mechanism. The Armstrong generator is included in one of the Claims of this Application.
Over time, the inventor was able to recognize what actually occurs in the Windraider process and how to control it, something also included in the Claims to this Application. Remarkably, and as will be explained with the assistance of the DRAWINGS, the Windraider process operates on nearly an infinite number of points along the side of the Oscillating wing which are constantly changing as the Oscillating wing oscillates, extracting energy from the air flow, which slows the air flow increasing its Static pressure, and thus maintaining the force rotating the Oscillating wing. This very rapidly increases until the extraction reaches the Betz Limit of 59.3% which, because the Oscillating wing is extracting energy from only one channel at a time means machine extracts 29.6% of the wind of the surface it faces.
29.6% does not immediately appear a high extraction rate in that the best wind turbines claim nearly twice as much. But up to now the context of almost all such comparisons are turbine v. turbine where the biggest differentiators are blades, how they perform as airfoils, the material they are made of and the engineering that determines their length and taper in an attempt to optimize the conflict created by more strength demanding more material, which creates more destructive forces which require more strength. Windraider is different. While there is a cost to increasing size, it follows, as will soon be evident, an entirely different paradigm, allowing it to be shockingly less expensive and far more reliable than a turbine. It is also not dangerous to humans (no danger of blades flying off) nor to birds or nor to other creatures, not noisy and not unattractive.
Perhaps most importantly, the Wind Wing is uncannily deployable. Almost any body shop should be capable of fabricating one in a few days. This means that should the global warming situation become significantly more acute, something there is every reason to believe is likely to occur, the United States can deploy them in tens if not hundreds of thousands in a matter of months. To the extent these devices fulfill their promise of providing half of the Average American Home's electricity needs it could reduce the Country's dependence on fossil fuels by as much as 30% and very possibly more.
It has been a long developing intention of the inventor that Governments. NGOs, corporations and others build web sites providing location-sensitive recommendations toward the construction of $20 Models, taking into account the respective environmental situations, most suitable materials, specific dimensions and fabrication guidelines so as to optimize $20 Models in some, if not all of the areas of the world where they can improve the lives of local impoverished communities. Such a development could be extended to include Tower Models as well. It is his hope that this will someday be the final development in the invention of Windraider.